Phoenix Suns
While the Bucks don't have an inner-conference rivalry with the Suns like they do with the Pacers or Celtics, there are still several other factors that make this a must-see matchup.
First off, the sheer collection of offensive talent on display from both sides would be unreal. For the Bucks, there is Antetokounmpo, Lillard and Middleton, three players who can score from all over. On the other end of things, there is Kevin Durant, Devin Booker and Bradley Beal, three of the smoothest three-level scorers in the NBA. The star power between the two franchises is undeniable.
Also, facing Phoenix would allow the Bucks to catch up with an old friend, as Mike Budenholzer is now the leading voice for the Suns. The championship-winning coach is now the head coach for the team he defeated to earn that title. His first game as the head coach being against a team he has plenty of history with would certainly be an eye-catching lense to watch this game through.
Due to the 2021 NBA Finals, there will always be a little extra flare in the matchups when these two teams meet up, especially with several key components from that series still on the floor.